Grapnel Gun

The Grapnel Gun is one of if not the most used gadgets in the game. It allows Batman to move around the city with ease by deploying a retractable cord at a target and pulling him to it. Since Arkham Asylum it has been given some upgrades. It now fires at a much longer distance and has a boost ability that slingshots the Dark Knight over a chosen target into a glide without out touching the ground, but the latter requires completion of a side mission to upgrade. It's a good idea to get acquainted with the distance it fires just to be ready.